Footprinting via Cached Pages

First of all, to know how to use cached data from search engines in hacking, we need to know what is cached data. Cached data is the data which is stored temporarily in the memory with an aim to provide faster loading of web pages.

Take an example : You might have observed that when you open any website for the first time in your browser (not using incognito mode), it will take some time to load the webpage. But then you close that webpage and try to re-visit the same page. Here, visiting the webpage another time will load it faster than the time it took at the first time. This is because, when you visit any page on internet, your browser captures the page data and stores it in the cache memory. On re-visiting the page, the elements of some part of the page are loaded from cache (offline) and this is why it takes less time.

The search engines have a similar process to do. When one visits a webpage via search engine, it stores the page in its cache memory. And this makes it faster to provide us results of the query we searched.

Google Cached Pages :

Google takes a snapshot of each page it examines and caches (stores) that version as a back-up. The cached version is what Google uses to judge if a page is a good match for your query.

Practically every search result includes a Cached link. Clicking on that link takes you to the Google cached version (old version captured by search engine) of that web page, instead of the current version of the page. This is useful if the original page is unavailable because of:

• Internet congestion
• A down, overloaded, or just slow website
• The owner’s recently removing the page from the Web

You can always access page’s cached version faster than the page itself as we all know that google’s servers are typically much more faster than any web servers.

• When Google displays the cached page, a header at the top serves as a reminder that what you see isn’t necessarily the most recent version of the page.
• The Cached link will be omitted for sites whose owners have requested that Google remove the cached version or not cache their content, as well as any sites Google hasn’t indexed.
• If the original page contains more than 101 kilobytes of text, the cached version of the page will consist of the first 101 kbytes (120 kbytes for pdf files).

Why to use Google Cached Pages?

Google Cache can be used for various purposes few of which are as follows:

• To see the contents of the page (if the original site is temporarily down).
• To see the content of the dynamically generated page (if the original page has been updated since the cache and no longer contains the information you need. Thus, if Google returns a link to a page that appears to have little to do with your actual query, or if you can’t find the information you’re seeking on the current version of the page, take a look at the cached version).
• To access websites blocked in your country.
• To more quickly access the information of a slow loading page. 
• To avoid registrations/subscriptions or advertisements on a webpage.

How to find Cached Webpages? 

1. Just go to Google Web Search text box and add the keyword cache: in front of the URL that you would like to see. Ex. cache:gtu.ac.in
2. There is “cached” link in each of the Google Web Search results, except for those web pages that do not allow Google Web Search to cache or snapshot on them. If there is this “Cached” link, just click. (See the snapshot provided above, click on it to view in full size)

With reference to Google Webmaster Tools Help on Remove a page or site from Google’s search results, a web page will not be available in Google Cache database if it is not visible to search engine crawler.